<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
         *{
            margin: 0px;
            padding: 0px;
        }
        .box1，.box2,.box3{
            width: 100vw;
            height: 100vh;
            display: flex;
            justify-content: center;
        }
        .d1{
            width: 200px;
            height: 200px;
            background-color: red;
        }
        .d2{
            width: 200px;
            height: 200px;
            background-color: green;
        }
        .d3{
            width: 200px;
            height: 200px;
            background-color:blue;
        }
        .box1{
            display: flex;
            justify-content: space-around;
        }
        .box2{
            display: flex;
            justify-content: space-between;
        }
    </style>
</head>
<body>
    <div class="box1">
        <div class="d1">1</div>
        <div class="d2">2</div>
        <div class="d3">3</div>
    </div>
    <div class="box2">
        <div class="d1">1</div>
        <div class="d2">2</div>
        <div class="d3">3</div>
    </div>
    <div class="box3">
        <div class="d1">1</div>
        <div class="d2">2</div>
        <div class="d3">3</div>
    </div>
</body>
</html>